Phosphaalkyne hydrometalation: Synthesis and reactivity of the complexes [Ru(P=CHCMe3)Cl(CA)(PPh3)2] (A = O, S)

Article abstract of DOI:10.1021/om980204c

The reaction of [RuHCl(CO)(PPh₃)₃] (1a) with P≡CCMe₃ results in the formation of the phosphaalkenyl complex [Ru(P=CHCMe₃)Cl(CO)(PPh₃)₂] (2a). Being coordinatively unsaturated, 2a reacts reversibly with CO to provide [Ru(P=CHCMe₃)Cl(CO)₂(PPh₃)₂] (3) and with isonitriles (CNR) to provide [Ru(P=CHCMe₃)Cl(CNR)(CO)(PPh₃)₂] [R = CMe₃ (4a), C₆H₃Me₂-2,6 (4b)]. With an excess of CNCMe₃, the salt [Ru(P=CHCMe₃)(CNR)₂(CO)(PPh₃)₂]-Cl 5(Cl) is obtained. The anionic bidentate ligand K[H₂B(bta)₂] (bta = benzotriazolyl) reacts with 2a via chloride displacement to provide [Ru(P=CHCMe₃){H₂B(bta)₂}(CO)(PPh ₃)₂] (6) while the facially tridentate macrocycle 1,4,7-trithiacyclononane ([9]aneS₃) provides [Ru-(P=CHCMe₃)(CO)(PPh₃)([9]aneS₃)]Cl 7(Cl). The thiocarbonyl complex [Ru{P=CHCMe₃)-Cl(CS)(PPh₃)₂] (2b), obtained from [RuHCl(CS)(PPh₃)₃] (1b) and P≡CCMe₃, reacts with [Et₂NH₂][S₂CNEt₂] or [9]aneS₃ to provide [Ru(P=CHCMe₃)(S₂CNEt₂)(CS)(PPh ₃)₂] (8) and [Ru(P=CHCMe₃)(CS)(PPh₃)([9]aneS₃)]Cl 9(Cl), respectively. The salt 5(Cl) or the neutral complex 4a react slowly with air (accelerated by base), to provide the λ⁵-phosphaalkenyl-metallacycle [Ru{P(=O)C(CMe₃)C(=O)}(CNCMe₃)₂(PPh ₃)₂] (10). The reactions of 1a with sodium formate or ferrocene carboxylate provides the complexes [Ru(P=CHCMe₃)(O₂CR)-(CO)(PPh₃)₂] (R = H (11a), C₅H₄Fe(η-C₅H₅) (11b)). The X-ray crystal structure of 11a is reported.

Full text of DOI:10.1021/om980204c

4744
Organometallics 1998, 17, 4744-4753
P h osp h a a lk yn e Hyd r om eta la tion : Syn th esis a n d
Rea ctivity of th e Com p lexes
[Ru (P dCHCMe3)Cl(CA)(P P h 3)2] (A ) O, S)
Robin B. Bedford,† Anthony F. Hill,*,† Cameron J ones,*,‡ Andrew J . P. White,†
David J . Williams,† and J ames D. E. T. Wilton-Ely†
Departments of Chemistry, Imperial College of Science, Technology and Medicine,
South Kensington, London, U.K. SW7 2AY, and University of Wales, Singleton Park,
Swansea, U.K. SA2 8PP
Received March 18, 1998
The reaction of [RuHCl(CO)(PPh3)3] (1a ) with PtCCMe3 results in the formation of the
phosphaalkenyl complex [Ru(PdCHCMe3)Cl(CO)(PPh3)2] (2a ). Being coordinatively unsat-
urated, 2a reacts reversibly with CO to provide [Ru(PdCHCMe3)Cl(CO)2(PPh3)2] (3) and
with isonitriles (CNR) to provide [Ru(PdCHCMe3)Cl(CNR)(CO)(PPh3)2] [R ) CMe3 (4a ),
C6H3Me2-2,6 (4b)]. With an excess of CNCMe3, the salt [Ru(PdCHCMe3)(CNR)2(CO)(PPh3)2]-
Cl 5(Cl) is obtained. The anionic bidentate ligand K[H2B(bta)2] (bta ) benzotriazolyl) reacts
with 2a via chloride displacement to provide [Ru(PdCHCMe3){H2B(bta)2}(CO)(PPh3)2] (6)
while the facially tridentate macrocycle 1,4,7-trithiacyclononane ([9]aneS3) provides [Ru-
(PdCHCMe3)(CO)(PPh3)([9]aneS3)]Cl 7(Cl). The thiocarbonyl complex [Ru{PdCHCMe3)-
Cl(CS)(PPh3)2] (2b), obtained from [RuHCl(CS)(PPh3)3] (1b) and PtCCMe3, reacts with
[Et2NH2][S2CNEt2] or [9]aneS3 to provide [Ru(PdCHCMe3)(S2CNEt2)(CS)(PPh3)2] (8) and
[Ru(PdCHCMe3)(CS)(PPh3)([9]aneS3)]Cl 9(Cl), respectively. The salt 5(Cl) or the neutral
complex 4a react slowly with air (accelerated by base), to provide the λ5-phosphaalkenyl-
metallacycle [Ru{P(dO)C(CMe3)C(dO)}(CNCMe3)2(PPh3)2] (10). The reactions of 1a with
sodium formate or ferrocene carboxylate provides the complexes [Ru(PdCHCMe3)(O2CR)-
(CO)(PPh3)2] (R ) H (11a ), C5H4Fe(η-C5H5) (11b)). The X-ray crystal structure of 11a is
reported.
In tr od u ction
to provide σ-vinyl complexes,3 although in recent times
more complicated processes have been uncovered for
terminal alkynes including the formation of alkynyl,4
vinylidene,5 alkylidene,6 and alkylidyne complexes.7
We find that the hydroruthenation of phosphaalkynes
does indeed proceed via simple and regioselective ad-
dition of the ruthenium hydride bond across the PtC
multiple bond to provide phosphaalkenyl complexes.
Phosphaalkenyl complexes have been prepared previ-
ously;8 however, it should be noted that in all prior cases
the “PdCR2” ligands bore either bulky kinetically
stabilizing substituents (CR2 ) C(SiMe3)2, C(OSiMe3)-
C6H2Me3-2,4,6) or π-dative thermodynamically stabiliz-
ing substituents (R ) OSiMe3, NMe2). The present
The coordination chemistry of phosphaalkynes has
proven to be an extremely fertile area of growth in
recent times.1 Notwithstanding the simple coordination
of phosphaalkynes to a metal center, by far the most
intriguing aspect of this chemistry has been the many
oligomerization processes which are effected by transi-
tion metals. In this respect, analogy is often made to
superficially related transition metal mediated oligo-
merizations of alkynes. This viewpoint has considerable
merit, although departures from the analogy are equally
inspiring. Our own perspective on phosphaalkyne
coordination chemistry is to pursue this analogy in the
direction of other classical reactions of alkynes with
metal centers. For example we have shown that alkyne
metathesis by alkylidyne complexes finds parallel in
phosphaalkyne chemistry.2 This paper is concerned
with the hydrometalation of phosphaalkynes by ruthe-
nium hydrido complexes. The reactions of alkynes with
hydride complexes of ruthenium or osmium typically
proceeds via hydrometalation of the -CtC- triple bond
(3) For a recent review covering the hydroruthenation of alkynes
see: Hill, A. F. In Comprehensive Organometallic Chemistry II; Abel,
E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon: Oxford, U.K,
1995; Vol. 7.
(4) Bohanna, C.; Esteruelas, M. A.; Herrer, J .; Lopez, A. M.; Oro, L.
A. J . Organomet. Chem. 1995, 498, 199.
(5) Bourgault, M.; Castillo, A.; Esteruelas, M. A.; On˜ate, E.; Ruiz,
N. Organometallics 1997, 16, 636. Esteruelas, M. A.; Oro, L. A.; Valero,
C. Organometallics 1995, 14, 3596.
(6) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E, Oro, L. A.; Valero, C.;
Zeier, B. J . Am. Chem. Soc. 1995, 117, 7935. Esteruelas, M. A.; Lahoz,
F. J .; On˜ate, E.; Oro, L. A.; Zeier, B. Organometallics 1994, 13, 4258.
Esteruelas, M. A.; Lahoz, F. J .; Lopez, A. M.; On˜ate, E.; Oro, L. A.
Organometallics 1994, 13, 1669.
(7) Weber, B.; Steinert, P.; Windmuller, B.; Wolf, J .; Werner, H. J .
Chem. Soc., Chem. Commun. 1994, 2595.
† Imperial College (e-mail: a.hill@ic.ac.uk).
‡ University of Wales (e-mail: c.a.jones@swansea.ac.uk).
(1) For reviews see: Nixon, J . F. Chem. Ind. 1993, 11, 404; Coord.
Chem. Rev. 1995, 145, 201; 1988, 88, 1327; Chem. Soc. Rev. 1995, 24,
319; Phosphorus, Sulfur Silicon Relat. Elem. 1994, 93, 87; 1990, 49,
463; 1987, 30, 471; Endeavor 1991, 15, 49.
(2) Hill, A. F.; Howard, J . A. K.; Spaniol, T. P.; Stone, F. G. A.;
Szameitat, J . Angew. Chem., Int. Ed. Engl. 1989, 28, 210.
(8) For a recent review on the chemistry of phosphaalkenyl com-
plexes see: Weber, L. Angew. Chem., Int. Ed. Engl. 1996, 35, 271.
S0276-7333(98)00204-0 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 09/24/1998

Phosphaalkyne Hydrometalation
Organometallics, Vol. 17, No. 21, 1998 4745
40.8 [d, CMe3, 2J (PC) ) 10.7], 30.8 [d, CH3, 3J (PC) ) 14.3 Hz]
ppm; 31P{1H}, 450.4 [t, PdC, 2J (P2P) ) 10.0], 33.9 [d, PPh3,
2J (P2P) ) 10.0 Hz] ppm. FAB-MS: m/z ) 940 (64) [M + nba]+,
791 (9) [M - H]+, 689 (24) [HM - HPCHR]+, 363 (32)
[RuPPh3]+, 263 (100) [HPPh3]+. Anal. Found: C, 63.9; H, 5.6.
Calcd for C42H40ClOP3Ru: C, 63.8; H, 5.1. NB: The complex
[Ru(PdCHAd)Cl(CO)(PPh3)2] (2c) (Ad ) adamantyl) was
observed from the reaction of 1a with PtC-Ad, however due
to its high solubility, the complex was never adequately
isolated free of PPh3. 31P{1H}NMR: 457.7 [t, PdCH, J (P2P)
) 10.5], 34.2 [d, PPh3, J (P2P) ) 10.5 Hz]. No reaction was
observed between 1a and the sterically cumbersome Pt
approach provides, for the first time, monosubstituted
phosphaalkenyl ligands without recourse to such sta-
bilization in addition to reassuringly supporting the
alkyne/phosphaalkyne analogy. Aspects of this work
have formed the basis of preliminary reports.9,10 In the
interim, it has been shown by Regitz that tin hydrides
will also hydrometalate phosphaalkynes but with the
opposite regiochemistry of addition across the PtC
multiple bond.11
Exp er im en ta l Section
t
CC6H2 Bu3-2,4,6.
Gen er a l Com m en ts. All manipulations were routinely
carried out under anaerobic conditions using conventional
Schlenk tube and vacuum line techniques. However, none of
the new compounds showed marked air-sensitivity during
workup or subsequent spectroscopic characterization. Solvents
were distilled from appropriate drying agents (ethers and
parafins from Na/K alloy and benzophenone; dichloromethane
from CaH2) under an atmosphere of dry nitrogen and purged
with nitrogen prior to use. The complexes [RuHCl(CA)(PPh3)3]
P r ep a r a tion of [Ru (P dCHCMe3)Cl(CS)(P P h 3)2] (2b). A
solution of [RuHCl(CS)(PPh3)3] (1.00 g, 1.03 mmol) in dichlo-
romethane (50 mL) was treated with PtCCMe3 (0.43 mL, ca.
2.3 equiv) and stirred for 1 h and the mixture then freed of
volatiles in vacuo. The residue was dissolved in dichloro-
methane (50 mL) and diethyl ether (60 mL) added. Slow
reduction in solvent volume provided crystals of the orange
product, which were washed with diethyl ether (20 mL),
hexane (20 mL), and dried in vacuo. Yield: 0.74 g (89%). IR
CH2Cl2: 1280 [ν(CS)] cm-1; Nujol, 1586, 1571, 1267 [ν(CS)],
1246, 919, 861, 845 cm-1. NMR (CDCl3, 25 °C): 1H, δ 0.99 [s,
9 H, CH3], 7.35-7.71 [m, 31 H, C6H5 + PdCH] ppm; 13C{1H}
(A ) O,12 S13) and the compounds PtCCMe3 and K[H2B-
14
(bta)2]15 were prepared according to published procedures. All
other reagents were used as received from commercial sources.
1H, 13C{1H}, and 31P{1H} NMR spectra were recorded with a
J EOL J NM EX270 NMR spectrometer and calibrated against
internal SiMe4 (1H), internal CDCl3 (13C), or external H3PO4
(31P) references. “tV” refers to virtual triplet resonances
characteristic of a trans-Ru(PPh3)2 arrangement with apparent
coupling constants being given. Infrared spectra were re-
corded both as dichloromethane solutions and Nujol mulls
using Perkin-Elmer 1720-X or Mattson Series 1 FT-IR spec-
trometers. Characteristic “fingerprint” bands for PPh3 are
omitted. FAB-mass spectrometry was carried out using an
Autospec Q instrument with 3-nitrobenzyl alcohol (nba) as a
matrix. Compositional assignments are based on simulation
of isotopic distributions; “M” refers to the molecular ion with
the exception of salts for which it refers to the cationic complex.
FAB-MS data are reported in the form m/z (% abundance)
[assignment]. Elemental analysis was carried out by the
Imperial College Microanalytical Service. In the case of
analytical data for partial solvates, the stoichiometry was
2
(CH2Cl2/CDCl3, 25 °C), δ 297.7 [t, CS, J (P2C) ) 15.2], 183.2
[d, PdC, 1J (PC)) 57.1], 134.7 [tv, C2,6(C6H5), J (P2C) ) 5.3],
131.2 [tv, C1(C6H5), J (P2C) ) 23.2], 130.2 [s, C4(C6H5)], 128.0
[tv, C3,5(C6H5), J (P2C) ) 5.4], 41.0 [d, CMe3, 2J (PC) ) 9.0], 31.0
[d, CH3, 3J (PC) ) 12.5 Hz] ppm; 31P{1H}, 445.2 [t, PdC, 2J (P2P)
) 12.3], 33.3 [d, PPh3, 2J (P2P) ) 12.2 Hz] ppm. FAB-MS: m/z
956 (39) [M + nba]+, 705 (5) [HM - HPCHR]+, 694 (19) [M +
nba - PPh3]+, 670 (21) [HM - Cl - HPCHR]+. Anal. Found:
C, 62.4; H, 5.1. Calcd for C42H40ClP3RuS: C, 62.6; H, 5.0.
P r epar ation of [Ru (P dCHtBu )Cl(CO)2(P P h 3)2] (3). Car-
bon monoxide was passed through a solution of [Ru(PdCHt-
Bu)Cl(CO)(PPh3)2] (2a ; 0.15 g, 0.19 mmol) in dichloromethane
(4 mL) for 2 min. Diethyl ether (20 mL) was added and the
mixture cooled to -10 °C for 12 h to provide pale yellow
crystals. Yield: 0.13 g (84%). The compound must be stored
under an atmosphere of carbon monoxide due to very facile
decarbonylation. For this reason satisfactory elemental mi-
croanalytical data were not obtained. IR CH2Cl2: 2023, 1969
1
confirmed, where possible, by H NMR integration.
[ν(CO)] cm-1; Nujol, 2024, 1975, 1256, 1096sh, 1090, 861 cm-1
.
P r ep a r a tion of [Ru (P dCHtBu )Cl(CO)(P P h 3)2] (2a ). A
solution of [RuHCl(CO)(PPh3)3] (1a ) (1.00 g, 1.05 mmol) in
dichloromethane (50 mL) was treated with PtCCMe3 (0.43
mL) and stirred for 1 h during which time the solution turned
bright orange. The solvent was removed and the residue
washed with diethyl ether (2 × 10 mL) to remove PPh3. The
remaining solid was crystallized from a mixture of dichloro-
methane and diethyl ether. Yield: 0.76 g (92%). IR CH2Cl2:
1929 [ν(CO)] cm-1; Nujol, 1929 sh, 1918 [ν(CO)], 1586, 1571,
1356, 1308, 1247, 863 cm-1. NMR (CH2Cl2/CDCl3, 25 °C): 1H,
δ 0.94 [s, 9 H, CH3], 7.12 [dt, 1 H, PdCH, 2J (PH) ) 16.2,
4J (P2H) ) 2.7 Hz], 7.42, 7.63 [m × 2, 30 H, C6H5] ppm; 13C{1H},
NMR (CD2Cl2, 25 °C): 1H, δ 0.87 [s, 9 H, CH3], 7.39, 7.88 [m ×
2
2, 30 H, C6H5], 8.03 [d, 1 H, PdCH, J (PH) ) 18.9 Hz] ppm;
13C{1H}, δ 198.7, 193.0 [t (br) × 2, RuCO, 2J (PC) not resolved],
1
196.8 [d, PdC, J (PC)) 62.5 Hz], 134.2 [tv, C2,6(C6H5)], 133.1
[tv, C1(C6H5), J (P2C) ) 26.8], 130.1 [s, C4(C6H5)], 128.0 [tv, C3,5
-
2
(C6H5), J (P2C) ) 5.4], 41.8 [d(br), CMe3, J (PC) not resolved],
30.4 [d, CH3, 3J (PC) ) 12.5 Hz] ppm; 31P{1H}, 369.5 [s (br),
2
PdC, J (P2P) not resolved], 22.1 [s(br), PPh3] ppm. FAB-MS:
m/z ) 940 (41) [M - CO + nba]+, 819 (18) [M]+, 789 (2) [M -
H
- CO]+, 689 (24) [M - HPdCHR - CO]+, 363 (24)
[RuPPh3]+, 263 [HPPh3]+.
P r ep a r a tion of[Ru (P dCHCMe3)Cl(CNtBu )(CO)(P P h 3)2]
(4a ). [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a ; 0.10 g, 0.13 mmol)
was suspended in diethyl ether (25 mL) and pivalo isocyanide
(CNCMe3, 0.015 mL, 0.011 g, 0.13 mmol) added. The reaction
was stirred for 30 min and the yellow precipitate filtered off,
washed with diethyl ether (10 mL), hexane (10 mL), and dried
in vacuo. Yield: 0.10 g (91%). The product can be recrystal-
lized from mixtures of dichloromethane and ethanol. IR
CH2Cl2: 2148 [ν(CN)], 1961 [ν(CO)] cm-1; Nujol, 2148 [ν(CN)],
2
1
δ 202.4 [t, CO, J (P2C) ) 15.2], 184.9 [d, PdC, J (PC)) 58.9],
134.4 [tv, C2,6 (C6H5), J (P2C) ) 5.4], 132.2 [tv, C1(C6H5), J (P2C)
) 22.3], 130.2 [s, C4(C6H5)], 128.1 [tv, C3,5(C6H5), J (P2C) ) 5.4],
(9) Bedford, R. B.; Hill, A. F.; J ones, C. Angew. Chem., Int. Ed. Engl.
1996, 35, 547.
(10) Hill, A. F.; J ones, C.; White, A. J . P.; Williams, D. J .; Wilton-
Ely, J . D. E. T. Chem. Commun. 1998, 367.
(11) Schmidz, M.; Go¨ller, R.; Bergstra¨sser, U.; Leininger, S.; Regitz,
M. Eur. J . Inorg. Chem. 1998, 227.
(12) Laing, K. R.; Roper, W. R. J . Chem. Soc., A. 1970, 2149.
(13) Brothers, P. J .; Roper, W. R. J . Organomet. Chem. 1983, 258,
73.
(14) Becker, G.; Gresser, G.; Uhl, W. Z. Naturforsch. B. 1981, 36,
16.
1930 [ν(CO)], 1587, 1571, 1311, 1240, 1201, 968, 890, 862 cm-1
.
NMR (CDCl3, 25 °C): 1H, δ 0.79 [s, 9 H, CH3], 0.97 [s, 9 H,
CH3], 7.29-7.95 [m, 31 H, C6H5 and PdCH] ppm; 31P{1H},
389.8 [t, PdC, J (P2P) ) 11.7], 24.6 [d, PPh3, J (P2P) ) 11.7
Hz] ppm. FAB-MS: m/z ) 953 (14) [M + CNtBu]+, 874 (5)
[M]+, 844 (1) [M - CO]+, 789 (2) [M - CNtBu]+, 772 (15) [HM
- HPCHR]+, 744 (10) [HM - CO - HPCHR]+, 709 (11) [Ru-
(15) Lalor, F. J .; Miller, S. M.; Garvey, N. Polyhedron 1990, 9, 63.
Lalor, F. J .; Miller, S. M.; Garvey, N. J . Organomet. Chem. 1988, 356,
C57.

4746 Organometallics, Vol. 17, No. 21, 1998
Bedford et al.
(CNtBu)(PPh3)2]+, 689 (3) [RuCl(CO)(PPh3)2]+, 654 (6) [Ru(CO)-
(PPh3)2]+, 625 (6) [Ru(PPh3)2]+, 363 (22) [RuPPh3]+. Anal.
Found: C, 62.2; H, 5.3; N, 1.5. Calcd for C47H49ClNOP3Ru‚
0.5CH2Cl2: C, 62.3; H, 5.5; N, 1.5.
initial color change to yellow. Filtration through diatomaceous
earth was followed by evaporation of the solvent from the
filtrate under reduced pressure. The crude product was
triturated in diethyl ether (10 mL) in an ultrasound bath to
provide a pale yellow solid, which was filtered off, washed with
diethyl ether (5 mL), and dried in vacuo. Yield: 0.08 g (42%).
The product can be recrystallized from dichloromethane and
diethyl ether. IR (Nujol): 2435, 2418 [ν(BH2)], 1959 [ν(CO)],
1295, 1273, 1241, 1190, 1147, 1133, 1104, 1075, 934, 868, 844
P r ep a r a tion of [Ru (P dCHCMe3)Cl(CNC6H3Me2-2,6)-
(CO)(P P h 3)2] (4b). [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a , 0.15
g, 0.19 mmol) was dissolved in dichloromethane (5 mL) and
2,6-dimethylphenyl isocyanide (0.030 g, 0.23 mmol) added. The
reaction was stirred for 5 min and then freed of volatiles in
vacuo. The residue was crystallized from a mixture of dichlo-
romethane and diethyl ether, washed with diethyl ether (10
mL), and dried in vacuo. Yield: 0.12 g (69%). IR CH2Cl2:
2109 [ν(CN)], 1960 [ν(CO)] cm-1; Nujol, 2121, 2111sh [ν(CN)],
1962 [ν(CO)], 1586, 1573, 1314, 1250, 863 cm-1. NMR (CD2Cl2,
25 °C): 1H, δ 0.85 [s, 9 H, C(CH3)3], 2.08 [s, 6 H, C6H3(CH3)2],
6.96 [d, 2 H, H3,5(C6H3)], 7.05 [t, 1 H, H4(C6H3), J (HH) ) 6.9
Hz], 7.27, 7.80 [m × 2, 30 H, C6H5], 8.11 [dt, 1 H, PdCH,
2J (PH) ) 19.2 Hz, 4J (PP) discernible but not resolved] ppm;
13C{1H}, 200.8 [t, RuCO, 2J (P2C) ) 12.5], 195.1 [dt, PdCH,
2J (PC) ) 64.2, 3J (P2C) ) ca. 4.5], 161 [br, CNR], 134.31 [tv,
C1(C6H5), J (P2C) ) 17.0], 134.27 [tv, C2,6(C6H5), J (PC) not
resolved], 129.5 [s, C4(C6H5)], 127.9 [C3,5(C6H3)], 127.5 [tv,
1
cm-1. NMR (CDCl3, 25 °C): H, δ 0.81 [s, 9 H, CH3], 3.45 [s
(br), 2 H, BH2], 6.9-8.0 [m, 39 H, C6H5, C6H4 + PdCH] ppm;
31P{1H}, 391.0 [s, PdC], 28.9 [s, PPh3] ppm. FAB-MS: m/z )
1005 (12) [M + 2H]+, 743 (25) [M + 2H - PPh3]+, 655 (52)
[HM - HPCHR - H2B(bta)2]+, 625 (27) [Ru(PPh3)2]+, 363 (42)
[RuPPh3]+. Anal. Found: C, 56.8; H, 4.6; N, 7.6. Calcd for
C
54H50BN6P3ORu‚2CH2Cl2: C, 57.3; H, 4.6; N, 7.2.
P r ep a r a tion of [Ru (P dCHtBu )(CO)(P P h 3)([9]a n eS3)]Cl
7(Cl). [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a ; 0.22 g, 0.28 mmol)
and [9]aneS3 (0.06 g, 0.33 mmol) were degassed under vacuum
and dissolved in dry, degassed dichloromethane (10 mL). After
being stirred for 20 h under nitrogen, the solution was taken
to dryness in vacuo. The resulting yellow oil was triturated
ultrasonically in diethyl ether (15 mL) to provide cream
crystals. These were washed with diethyl ether (10 mL),
petroleum ether (10 mL), and dried. Yield: 0.12 g (61%). The
product can be recrystallized from mixtures of dichloromethane
and diethyl ether. IR (Nujol): 1977 [ν(CO)], 1717, 1636, 1310,
2
C3,5(C6H5), J (P2C) ) 5.4], 41.8 [d, CMe3, J (PC) ) 12.5], 30.5
[d, (CH3)3, 3J (PC) ) 14.3 Hz], 18.3 [C6H3CH3] ppm; 31P{1H},
391.0 [t, PdC, J (P2P) ) 11.1], 24.4 [d, PPh3, J (P2P) ) 10.2
Hz] ppm. FAB-MS: m/z ) 1075 (3) [HM + nba]+, 940 (13)
[HM + H2O], 922 (42) [HM]+, 820 (92) [HM - HPCHR]+, 792
(72) [HM - HPdCHR - CO]+, 757 (15) [HM - HPdCHR -
CO - Cl]+, 558 (33) [M - HPdCHR - PPh3]+, 523 (8) [M -
1270, 1234, 943, 912, 884, 824 cm-1
. NMR (CDCl3, 25 °C):
1H, 1.02 [s, 9 H, CH3], 1.6, 2.1, 2.4, 2.8, 3.4, 3.6, 3.9 [m × 7, 12
HPdCHR - PPh3 - Cl]+, 494 (41) [M - HPdCHR - PPh3
-
H, SCH2], 7.45 [m, 15 H, C6H5], 8.94 [d, 1 H, PdCH, J (PH) )
Cl - CO]+, 363 (78) [RuPPh3]+, 263 (100) [HPPh3]+. Anal.
Found: C, 65.0 H, 5.7; N, 1.5. Calcd for C51H49ClNOP3Ru‚
H2O: C, 65.2; H, 5.5; N, 1.5.
18.8 Hz] ppm; 13C{1H}, 204.5 [d, PdC, J (PC) ) 64.3], 200.0
1
[d, CO, 2J (PC) ) 16.0], 134.2 [d, C2,6(C6H5), 2J (PC) ) 10.8],
1
132.5 [d, C1(C6H5), J (PC) ) 46.4], 131.4 [s, C4(C6H5)], 129.1
3
3
[d, C3,5(C6H5), J (PC) ) 10.7], 52.8 [d, SCH2, J (PC) ) 35.7],
43.2 [d, PdCC, 2J (PC) ) 10.7], 38.2, 35.9, 34.7 [SCH2], 31.2
[d, SCH2, 3J (PC) 42.8 Hz], 31.1[CH3] ppm; 31P{1H}, 357.5 [Pd
C], 37.7 [PPh3] ppm. FAB-MS: m/z ) 691 (100) [M + H2O]+,
571 (4) [HM - HPCHR]+, 516 (6) [HM - HPCHR - 2C2H4]+.
Anal. Found for 7(PF6): C, 40.9; H, 4.3. Calcd for C30H37F6P3-
RuS4‚CH2Cl2: C, 40.5; H, 4.3.
P r ep a r a tion of [Ru (P dCHtBu )(CNtBu )2(CO)(P P h 3)2]Cl
5(Cl). A solution of [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a ; 0.20
g, 0.25 mmol) in dichloromethane (15 mL) was treated with
pivalo isocyanide (0.06 mL, 0.04 g, 0.53 mmol). The mixture
was stirred for 2 h, and then all solvent was removed in vacuo.
A cream solid was then obtained by ultrasonic trituration of
the residue in hexane (15 mL). This product was washed with
hexane (10 mL) and dried in vacuo. Yield: 0.21 g (95%). The
salt could be recrystallized from a mixture of dichloromethane
and ethanol. IR CH2Cl2: 2179, 2156 [ν(CN)], 2021 [ν(CO)]
cm-1; Nujol, 2184, 2163 [ν(CN)], 2003, 1980 [ν(CO)], 1720,
1627, 1311, 1234, 1187, 931, 862, 846 cm-1. NMR (CDCl3, 25
°C): 1H, δ 0.66 [s, 9 H, NCCH3], 0.96 [s, 9 H, PCCH3], 1.18 [s,
9 H, NCCH3], 7.32-7.77 [m, 31 H, PC6H5 + PdCH] ppm;
31P{1H}, 336.8 [s, PdC], 33.5 [s, PPh3] ppm. FAB-MS: m/z )
921 (34) [M]+, 838 (100) [M - CNtBu]+, 810 (16) [M - CO -
CNtBu]+, 792 (10) [HM - CO - HPCHR]+, 735 (3) [HM -
CNtBu - HPCHR]+, 708 (14) [HM - CNtBu - CO - HPCHR]+,
576 (2) [M - PPh3]+, 547 (8) [M - CO - PPh3]+, 530 (26) [M
- CNtBu-PPh3]+, 363 (29) [RuPPh3]+. Anal. Found: C, 60.0;
H, 5.0; N, 2.6. Calcd for C52H58ClN2OP3Ru‚1.5CH2Cl2: C, 59.9;
H, 5.7; N, 2.6.
P r ep a r a tion of [Ru (P dCHtBu )(CNtBu )2(CO)(P P h 3)2]-
O2CH 5(O2CH). [Ru(PdCHtBu)(O2CH)(CO)(PPh3)2] (11a ;
0.10 g, 0.13 mmol) was dissolved in dichloromethane (10 mL)
and CNCMe3 (0.1 mL, excess) added. The mixture was stirred
for 30 min leading to a decolorization of the orange-yellow
solution. All solvent was removed and diethyl ether (20 mL)
added. Trituration in an ultrasound bath provided a colorless
solid which was filtered off, washed with diethyl ether (20 mL)
and hexane (20 mL), and dried in vacuo. Yield: 0.09 g (75%).
The salt was characterized by comparison of spectroscopic data
with those described above for 5(Cl).
P r ep a r a tion of [Ru (P dCHtBu )(S2CNEt2)(CS)(P P h 3)2]
(8). [Ru(PdCtBu)Cl(CS)(PPh3)2] (2b; 0.15 g, 0.19 mmol) and
[Et2NH2][S2CNEt2] (0.05 g, 0.23 mmol) were degassed in vacuo
and dissolved in dry, degassed dichloromethane (10 mL). An
immediate color change from orange to yellow was observed.
After 40 min of stirring, the solvent volume was reduced in
vacuo and dry, degassed ethanol (40 mL) added slowly to
precipitate the bright yellow product. This was filtered off,
washed with ethanol (10 mL) and petroleum ether (10 mL),
and dried in vacuo. Yield: 0.09 g (53%). The complex could
be recrystallized from a mixture of dichloromethane and
hexane. IR (Nujol): 1585, 1572, 1358, 1252 [ν(CS)], 1214, 917,
809, 849 cm-1. NMR (CDCl3, 25 °C): 1H, δ 0.81 [s, 9 H, CH3],
1.2, 1.8 [m × 2, 6 H, NCCH3], 2.72, 3.02 [m × 2, 4 H, CH2],
7.31, 7.68 [m × 2, 30 H, C6H5], 7.89 [d, 1 H, PdCH] ppm;
13C{1H}, δ 305.4 [dt, CS, J (P2C) ≈ J (PC) ) 12.7], 202.7 [d, S2C,
3J (PC) ) 23.2], 190.0 [d, PdC, J (PC) ) 62.5], 135.2 [tv,
C2,6(C6H5), J (P2C) ) 5.4], 133.9 [tv, C1(C6H5), J (P2C) ) 18.8],
128.9 [s, C4(C6H5)], 127.1 [tv, C3,5(C6H5), J (P2C) ) 5.4], 43.8,
43.4 [s x 2, CH2], 43.6 [d, PCMe3, J (PC) unresolved], 31.1 [d,
PCCCH3, J (PC) ) 12.5 Hz], 30.6, 30.5 [s x 2, 2 x NCCH3] ppm;
31P{1H}, 387.6 [s, PdC], 35.5 [s, PPh3] ppm. FAB-MS: m/z )
919 (20) [M]+, 818 (6) [HM - HPCHR]+, 658 (100) [M - PPh3]+,
556 (40) [HM - HPCHR - PPh3]+. Anal. Found: C, 59.8; H,
5.3; N, 1.6. Calcd for C47H50Cl2NP3Ru2S3: C, 60.0; H, 5.4; N,
1.5.
P r ep a r a tion of [Ru (P dCHtBu ){H2B(bta )2}(CO)(P P h 3)2]
(6). [Ru(PdCHtBu)Cl(CO)(PPh3)3] (2a ; 0.15 g, 0.19 mmol) and
K[H2B(bta)2] (0.06 g, 0.21 mmol) were degassed in vacuo and
then dissolved in degassed dichloromethane (5 mL) and
acetone (1 mL). The solution was stirred for 30 min after an
P r ep a r a tion of [Ru (P dCHtBu )(CS)(P P h 3)([9]a n eS3)]Cl
9(Cl). [Ru(PdCHtBu)Cl(CS)(PPh3)2] (2b; 0.20 g, 0.25 mmol)
and [9]aneS3 (0.05 g, 0.28 mmol) were degassed in vacuo and
then dissolved in dry, degassed dichloromethane (10 mL), and
the mixture was stirred for 18 h under nitrogen. All solvent

Phosphaalkyne Hydrometalation
Organometallics, Vol. 17, No. 21, 1998 4747
Ta ble 1. Cr ysta l Da ta a n d Da ta Collection a n d
Solu tion a n d Refin em en t Deta ils for
was removed in vacuo and the residual yellow oil triturated
ultrasonically in diethyl ether (15 mL) to provide an off-white
product. This was washed with diethyl ether (10 mL) and
hexane (10 mL) and dried in vacuo. Yield: 0.10 g (55%). The
salt could be recrystallized from a mixture of dichloromethane
and hexane. IR (Nujol): 1621, 1299, 1284 [ν(CS)], 1018, 941
[Ru (P dCHCMe3)(O2CH)(CO)(P P h 3)2] (11a )
Crystal Data
emp formula
Mr
C43H41O3P3Ru‚CHCl3
919.1
1
cm-1. NMR (CDCl3, 25 °C) H, δ 0.80-1.49, 2.10-3.75 [m ×
a-c (Å)
R-γ (deg)
V (Å3)
10.002(1), 12.219(1), 19.580(1)
88.55(1), 84.71(1), 67.28(1)
2197.9(2)
2, 12 H, SCH2], 0.99 [s, 9 H, CH3], 7.42-7.60 [m, 30 H, C6H5],
8.99 [d, 1 H, PdCH, 2J (HP) not resolved] ppm; 31P{1H}, 353.5
[s, PdCH], 36.3 [s, PPh3] ppm. FAB-MS: m/z 689 (4) [M]+,
631 (6) [M - 2C2H4]+, 588 (1) [HM - HPCHR]+. Anal. Found
for 9(PF6): C, 40.6; H, 4.2. Calcd for C30H37F6OP3RuS4‚CH2-
Cl2: C, 40.6; H, 4.3.
space grp
Z
P1h
2
Dcalcd (g cm-3
)
1.389
cryst size (mm)
0.40 × 0.17 × 0.10
Data Collection
293
P r ep a r a tion of [Ru {K2-C(dO)C(tBu )dP dO}(CNtBu )2-
(P P h 3)2] (10). [Ru(PdCHtBu)(CNtBu)2(CO)(PPh3)2]Cl (5(Cl);
0.10 g, 0.11 mmol) was dissolved in a mixture of dichloro-
methane (15 mL) and ethanol (5 mL) and stirred under air
with an excess of CNCMe3 (0.1 mL) for 5 d. All solvent and
excess CNCMe3 was removed in vacuo and the resulting oil
triturated ultrasonically in diethyl ether (15 mL). The color-
less product obtained was washed with diethyl ether (10 mL)
and hexane (10 mL) and dried in vacuo. Yield: 0.08 g (82%).
The product can be recrystallized from chloroform-ethanol
T (K)
diffractometer
wavelength
scan type
abs cor; max, min
transm
Siemens P4/PC
Cu KR, 1.541 78 Å
ω-scans (4.54 e 2θ e 120.0°)
ellipsoidal; 0.67, 0.43
no. of data
6504 unique; 5114 with F g 4σ(F) retained
Solution and Refinement
method
direct and difference Fourier
program
residuals
SHELXTL PC, version 5.03
mixtures. IR CH2Cl2: 2171, 2038 [ν(CN)], 1644 [ν(CdO)] cm-1
;
R1 ) 0.058, wR2 ) 0.143 (427 parameters)
e density max ) 0.88, min ) -1.06 e Å-3
Nujol, 2169, 2028 [ν(CN)], 1644 [ν(CdO)], 1234, 1189 [ν(PO)],
921, 890, 846 cm-1. NMR (CDCl3, 25 °C): 1H, δ 0.61 [s, 9 H,
NCCH3], 0.87 [s, 9 H, PCCH3], 1.27 [s, 9 H, NCCH3], 7.28-
washed with ethanol (10 mL) and hexane (10 mL) and dried
in vacuo. Yield: 0.08 g (64%). The product can be recrystal-
lized from chloroform-ethanol mixtures. IR: Nujol, 1926
2
7.73 [m, 30 H, PC6H5] ppm; 31P{1H}, 47.0 [t, PdO, J (P2P) )
25.2], 31.2 [d, PPh3, 2J (PP2) ) 25.2 Hz] ppm. FAB-MS: m/z )
856 (2) [M - CNtBu]+, 530 (2) [M - OPCRCO - PPh3]+. Anal.
Found: C, 59.4; H, 5.4; N, 3.2. Calcd for C52H57N2O2P3Ru‚
1.75CH2Cl2: C, 59.5; H, 5.6; N, 2.6. The complex was also
characterized crystallographically.10
[ν(CO)], 1585, 1571, 1311, 1249, 1107, 863, 809, 771 cm-1
;
CH2Cl2, 1920 [ν(CO)], 1646 cm-1. NMR (CDCl3, 25 °C): 1H, δ
0.62 [s, 9 H, CH3], 3.43 [s, 5 H, C5H5], 3.78, 3.94 [t x 2, 4 H,
C5H4,J (HH) ) 1.87 Hz], 7.3-7.8 [m, 31 H, PC6H5 + PCH] ppm;
31P{1H}, 419.7 [s(br), PCH], 36.7 [d, PPh3, J (PP) ) 8.0 Hz] ppm.
FAB-MS: m/z (%) [Fc ) ferrocenyl] ) 984 (25) [M]+, 956 (3)
[M - CO]+, 883 (36) [M - HPCHR]+, 755 (45) [M - FcCO2]+,
722 (100) [M - PPh3]+, 694 (32) [M - PPh3 - CO]+, 655 (51)
[M - FcCO2 - HPCHR]+, 625 (82) [Ru(PPh3)2]+, 363 (86)
[RuPPh3]+, 263 (68) [HPPh3]+. Anal. Found: C, 51.2; H, 4.1.
P r ep a r a t ion of [R u (P dCH t Bu )(O2CH )(CO)(P P h 3)2]
(11a ). [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a ; 0.10 g, 0.13 mmol)
was dissolved in dichloromethane (20 mL) and ethanol (10
mL). Sodium formate (0.02 g, 0.44 mmol) dissolved in water
(1 mL) and ethanol (10 mL) was added and the mixture stirred
for 5 min. The solvent volume was slowly reduced by rotary
evaporation resulting in formation of an orange microcrystal-
line product. This was washed with ethanol (20 mL) and
hexane (20 mL) and dried in vacuo. Yield: 0.09 g (87%). IR:
Nujol, 1922 [ν(CO)], 1554 [ν(CO2)], 1309, 1249, 1186, 970, 937,
863, 800 cm-1; CH2Cl2, 1924 [ν(CO)], 1552 [ν(CO2)] cm-1. NMR
(CDCl3, 25 °C): 1H, δ 0.66 [s, 9 H, CH3], 6.88 [dt, 1 H, O2CH,
J (HP) ) 1.32 Hz, J (HP2) not resolved], 7.3-7.5 [m, 31 H,
PC6H5 + PdCH] ppm; 13C{1H}, δ 205.7 [t, CO, J (P2C) ) 15.8],
187.4 [dt, PdC, 1J (PC) ) 59.2, 3J (P2C) ) 3.8 ], 171.3 [O2C],
134.5 [tv, C2,6(C6H5), J (P2C) ) 5.4], 131.4 [tv, C1(C6H5), J (P2C)
) 22.3], 130.1 [s, C4(C6H5)], 128.1 [tv, C3,5(C6H5), J (P2C) ) 6.6],
41.1 [d, CMe3, J (PC) 10.0], 31.2 [d, CH3, J (PC) ) 13.1 Hz],
ppm; 31P{1H}, 426.5 [t, PdCH, J (P2P) ) 8.0], 38.5 [d, PPh3,
J (P2P) ) 10.0 Hz] ppm. FAB-MS: m/z (%) ) 800 (11) [M]+,
755 (14) [M - O2CH]+, 727 (2) [M - CO - O2CH]+, 701 (30)
[M - HPCHR]+, 671 (12) [M - CO - HPCHR]+, 654 (65) [M
- O2CH - HPCHR]+, 626 (33) [M - CO - O2CH - HPCHR]+,
363 (50) [RuPPh3]+. Anal. Found: C, 61.9; H, 5.2. Calcd for
C
53H49FeO3P3Ru‚2.75CHCl3: C, 51.0; H, 4.0.
Cr ysta l Str u ctu r e Deter m in a tion of [Ru (P dCHtBu )-
(O2CH)(CO)(P P h 3)2] (11a ). A summary of the crystal data,
data collection, and refinement details is given in Table 1. The
structure was solved by direct methods, and all the major
occupancy non-hydrogen atoms were refined anisotropically
using full-matrix least squares based on F2 to give R1) 0.058,
and wR2 ) 0.143 for 5114 independent observed reflections
[|Fo| > 4σ(|Fo|), 2θ e 120°] and 427 parameters. Phenyl rings
were refined as optimized rigid bodies. Hydrogen atoms were
placed in calculated positions, assigned isotropic thermal
parameters, U(H) ) 1.2Ueq(C) [U(H) ) 1.5Ueq(C-Me)], and
allowed to ride on their parent atoms. Computations were
carried out using the SHELXTL PC program system (version
5.03, Siemens Analytical X-ray Instruments, Inc., Madison,
WI, 1994). Atomic coordinates, bond lengths and angles, and
thermal parameters have been deposited at the Cambridge
Crystallographic Data Centre (CCDC). Selected bond lengths
and angles are given in Table 2.
C
43H41O3P3Ru‚0.5CH2Cl2: C, 62.0; H, 5.0. Crystals obtained
from a mixture of chloroform and diethyl ether were charac-
terized crystallographically (vide infra).
Resu lts a n d Discu ssion
P r ep a r a tion of [Ru (P dCHtBu ){O2CC5H4F eC5H5}(CO)-
(P P h 3)2] (11b). [Ru(PdCHtBu)Cl(CO)(PPh3)2] (2a ; 0.10 g, 0.13
mmol) was dissolved in dichloromethane (20 mL) and ethanol
(10 mL). To this was added an ethanolic solution (5 mL) of
ferrocenecarboxylate sodium salt (prepared by the reaction of
ferrocenecarboxylic acid with aqueous sodium hydroxide, 0.05
g, 0.20 mmol) and the mixture stirred for 5 min. The solvent
volume was reduced by rotary evaporation to precipitate an
orange product. This was redissolved in dichloromethane and
filtered through diatomaceous earth. Ethanol was added and
the product precipitated by rotary evaporation. This was
The complex [RuHCl(CO)(PPh3)3] (1a ) reacts readily
with alkynes16 and diynes17 to provide alkenyl or enynyl
complexes (Scheme 1). While the precursor is coordi-
natively saturated, the replacement of the hydride
(16) Torres, M. R.; Vegas, A.; Santos, A. J . Organomet. Chem. 1986,
309, 169.
(17) Hill, A. F.; Melling, R. P. J . Organomet. Chem. 1990, 396, C22.
Hill, A. F.; Melling, R. P.; Thompsett, A. R. J . Organomet. Chem. 1991,
402, C8. Hill, A. F.; Harris, M. C. J .; Melling, R. P. Polyhedron 1992,
11, 781.

4748 Organometallics, Vol. 17, No. 21, 1998
Bedford et al.
scorpionates,21 sulfur-based macrocycles,22 triboronates,23
dithiocarbamates,24 and phosphonio dithiocarbox-
ylates.25 The complex 1a therefore appeared an ideal
substrate for investigating the potential hydrometala-
tion of phosphaalkynes, both from the point of view of
facility and the synthetic potential of the anticipated
product. A reaction rapidly ensues at room temperature
in dichloromethane between 1a and PtCCMe3 to pro-
vide a red solution from which a complex formulated
as [Ru(PdCHCMe3)Cl(CO)(PPh3)2] (2a ) may be isolated
in 92% yield. A similar reaction occurs between 1a and
adamantylphosphaalkyne; however, the product is highly
soluble and difficult to isolate free from PPh3 and,
accordingly, was not studied further. The phosphaalkyne
PtCC6H2(CMe3)3-2,4,6 fails to react with 1a under
ambient conditions, presumably due to the enormous
steric bulk of the aryl group. The complex 2a appears
to be indefinitely air-stable in the solid state and for
hours in solution. Two possible orientations of hydro-
metalation are conceivable (Scheme 1) involving Ru-P
(A) or Ru-C (B) bond formation, however, it is the
former regiochemistry (A) which is realized in the
ultimate product. The alternative orientation cannot
be excluded as a possible but reversible kinetic detour;
however, no evidence for its formation was obtained.
Notably, Regitz has very recently observed the opposite
regioselectivity of addition in the reactions of phos-
phaalkynes with tin hydrides.11
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 11a
Ru-C
1.808(6)
2.366(5)
2.378(2)
1.640(8)
1.522(9)
1.241(9)
Ru-P(1)
Ru-O(8)
Ru-P(3)
C-O
2.295(2)
2.182(5)
2.386(2)
1.135(8)
1.237(9)
Ru-O(6)
Ru-P(2)
P(1)-C(1)
C(1)-C(2)
C(7)-O(8)
C(7)-O(6)
C-Ru-O(8)
O(8)-Ru-P(1)
O(8)-Ru-O(6)
C-Ru-P(2)
P(1)-Ru-P(2)
C-Ru-P(3)
P(1)-Ru-P(3)
P(2)-Ru-P(3)
Ru-C-O
174.2(2)
91.3(1)
57.1(2)
89.4(2)
93.2(1)
90.6(2)
92.0(1)
174.8(1)
177.5(6)
85.6(4)
123.3(6)
C-Ru-P(1)
94.5(2)
117.1(2)
148.4(1)
90.5(1)
86.2(2)
89.0(1)
89.2(2)
119.1(3)
127.4(7)
94.0(4)
C-Ru-O(6)
P(1)-Ru-O(6)
O(8)-Ru-P(2)
O(6)-Ru-P(2)
O(8)-Ru-P(3)
O(6)-Ru-P(3)
C(1)-P(1)-Ru
P(1)-C(1)-C(2)
Ru-O(8)-C(7)
Ru-O(6)-C(7)
O(6)-C(7)-O(8)
Sch em e 1a
Despite repeated attempts to obtain structural data
to confirm the nature of 2a , severe positional disorder
was encountered. The formulation therefore rests,
albeit firmly, on spectroscopic data: FAB mass spec-
trometry reveals a substantial peak (53%) due to an
adduct of the matrix 3-nitrobenzyl alcohol. The pro-
tonated molecular ion (10%) is accompanied by frag-
mentation due to loss of the phosphaalkenyl ligand
(20%). The infrared spectrum (Nujol) is rather feature-
less, other than for a split absorption due to the carbonyl
ligand (1929, 1918 cm-1) and a weak absorption at 963
cm-1 which may arise in part from ν(PC). The 31P{1H}
NMR spectrum of 2a consists of a doublet resonance at
33.9 ppm due to the two equivalent phosphine ligands
and a triplet to very low field at 450.4 ppm showing a
coupling of ca. 10 Hz. This region of the 31P NMR
spectrum may be considered typical of phosphaalkenyl
ligands;8 however, this point will be returned to. In
CD2Cl2 the vinylic proton gives rise to a double triplet
resonance centered at δ 7.12 ppm showing coupling to
both the phosphaalkenyl phosphorus [2J (PC) ) 16.8 Hz]
and to the two chemically equivalent phosphine 31P
nuclei [4J (P2H) ) 2.3 Hz]. In C6D6 this resonance moves
to 7.43 ppm and is more clearly distinguished from those
due to the phosphine phenyl groups. The 13C{1H} NMR
spectrum of 2a includes a triplet resonance at 202.4 ppm
[J (P2C) ) 15.2 Hz] due to the carbonyl ligand and a set
of virtual triplet resonances for the phosphine phenyl
groups indicating a trans Ru(PPh3)2 arrangement, each
a
L ) PPh3 and R ) CMe3.
ligand by a σ-organyl group disfavors the recoordination
of the labile phosphine originally present. The resulting
16-electron complexes enter into ligand addition and
substitution reactions with a wide range of ligands
including CO,18 isocyanides,17,19 poly(azolyl) chelates,20
(18) Torres, M. R.; Perales, A.; Loumrhari, H.; Ros, J . J . Organomet.
Chem. 1990, 384, C61. Loumrhari, H.; Ros, J .; Torres, M. R.; Santos,
A.; Echavarren, A. M. J . Organomet. Chem. 1991, 411, 255.
(19) Montoya, J .; Santos, A.; Lo´pez, J .; Echavarren, A. M.; Ros,
Romero, A. J . Organomet. Chem. 1992, 426, 383. Montoya, J .; Santos,
A.; Echavarren, A. M.; Ros, J . J . Organomet. Chem. 1990, 390, C57.
(20) Cartwright, J .; Harman, A.; Hill, A. F. J . Organomet. Chem.
1990, 396, C31. Cartwright, J .; Hill, A. F. J . Organomet. Chem. 1992,
429, 229.
(21) Hill, A. F. J . Organomet. Chem. 1990, 395, C35. Alcock, N. W.;
Hill, A. F.; Melling, R. P. Organometallics 1991, 10, 3898.
(22) Cannadine, J . C.; Hector, A. L.; Hill, A. F. Organometallics
1992, 11, 2323. Cannadine, J . C.; Hill, A. F.; White, A. J . P.; Williams,
D. J .; Wilton-Ely, J . D. E. T. Organometallics 1996, 15, 5409.
(23) Burns, I. D.; Hill, A. F.; Thompsett, A. R.; Alcock, N. W.; Claire,
K. S. J . Organomet. Chem. 1992, 425, C8.
(24) Loumrhari, H.; Ros, J .; Torres, M. R. Polyhedron 1991, 18, 585.
(25) Hector, A. L.; Hill, A. F. J . Organomet. Chem. 1993, 447, C7.

Phosphaalkyne Hydrometalation
Organometallics, Vol. 17, No. 21, 1998 4749
Sch em e 2a
Ch a r t 1
complexes with linear M-P-C phosphavinylidene
ligands. In some cases this reaction is spontaneous
under ambient conditions and accompanied by a shift
to high field of the position of the 31P NMR resonance
by 30-116 ppm. In the case of 2a addition of carbon
monoxide occurs rapidly but reversibly at room tem-
perature. Thus the red color of 2a is immediately
discharged on addition of CO to provide pale yellow
solutions of [Ru(PdCHCMe3)Cl(CO)2(PPh3)2] (3). If the
complex is precipitated with hexane while under an
atmosphere of CO, a pale yellow solid is isolated in 84%
yield. The complex is however unstable in the absence
of excess carbon monoxide (precluding satisfactory
elemental microanalysis), reverting slowly to 2a when
stored as a solid or rapidly in solution. Thus while CO
coordination is rapid, so is dissociation.
Infrared spectroscopy indicates a cis-dicarbonyl ge-
ometry [Nujol: ν(CO) ) 2024, 1975 cm-1], while the
31P{1H} NMR spectrum suggests a trans-bis(phosphine)
arrangement indicated by the appearance of a doublet
resonance at 22.1 ppm. However, most remarkable in
this spectrum is the appearance of a broadened reso-
nance at 369.5 ppm which is moved 81 ppm to higher
field of that in 2a . The direction of this change in
chemical shift is opposite to those for the EAN-precise
complexes C and D. While there is no question as to
the coordination mode of the phosphaalkenyl ligand in
18-electron 3, this counterintuitive spectroscopic result
calls into question the nature of the bonding in 2a . We
suspect that the phosphaalkenyl ligand in 2a does not
involve a linear “phosphavinylidene” coordination but
rather that the complex is coordinatively unsaturated
with a bent and hence nucleophilic phosphaalkenyl
ligand. Consistent with this interpretation, the complex
2a has been found to react at phosphorus with a range
of electrophiles, e.g., HCl, MeI, ClAuPPh3, and HgCl2.9,29
The nature of the novel compounds obtained via elec-
trophilic attack will be discussed in a subsequent
paper.30 These reactions however point toward a nu-
cleophilic character for the phosphorus atom of the
a
L ) PPh3.
of these ligands being cis to the carbonyl ligand.
A
doublet resonance at 184.9 ppm [1J (PC) ) 58.9 Hz] is
assigned to the phosphaalkenyl PdC carbon, while the
CMe3 group gives rise to two doublets at 40.8 [2J (PC)
) 10.7] and 30.8 ppm [3J (PC) ) 14.3 Hz].
Ligan d Addition /Su bstitu tion Reaction s (Sch em e
2). The “RuCl(CO)(PPh3)2” fragment requires a further
3 valence electrons to complete its ideal effective atomic
number (EAN). Phosphaalkenyl ligands have been
observed to coordinate in two possible binding modes
to mononuclear centers (Chart 1). The M-P-C spine
can be nonlinear in which case there is a lone pair on
phosphorus, and the ligand provides one valence elec-
tron in a simple σ-bond (A). Alternatively, the M-P-C
spine may be linear in which case the ligand is consid-
ered to provide 3 valence electrons and might be
referred to as a “phosphavinylidene”. This dichotomy
is best illustrated by the class of complexes [M{PdC(Si-
Me3)2}(CO)x(η-C5R5)] (M ) Cr, Mo, W; R ) H, Me; x )
3 (C), 2 (D)).26-28 The complexes with a bent M-P-C
spine may be thermally decarbonylated to dicarbonyl
(26) Arif, A. M.; Cowley, A. H.; Nunn, C. M.; Quashie, S.; Norman,
N. C.; Orpen, A. G. Organometallics 1989, 8, 1878. Arif, A. M.; Cowley,
A. H.; Quashie, S. J . Chem. Soc., Chem. Commun. 1985, 428. Cowley,
A. H.; Norman, N. C.; Quashie, S. J . Am. Chem. Soc. 1984, 106, 5007.
(27) Gudat, D.; Niecke, E.; Malisch, W.; Hofmockel, U.; Quashie,
S.; Cowley, A. H.; Arif, A. M. Krebs, B.; Dartman, M. J . Chem. Soc.,
Chem. Commun. 1985, 1687.
(29) Bedford, R. B.; Hibbs, D. E.; Hill, A. F.; Hursthouse, M. B.;
Malik, K. M. A.; J ones, C. J . Chem. Soc., Chem. Commun. 1996, 1895.
(30) Bedford, R. B.; Hill, A. F.; J ones, C.; Wilton-Ely, J . D. E. T.
Manuscript in preparation.
(28) Niecke, E.; Metternich, H.-J .; Nieger, M.; Gudat, D.; Wenderoth,
P.; Malisch, W.; Hahner, C.; Reich, W. Chem. Ber. 1993, 126, 1299.

4750 Organometallics, Vol. 17, No. 21, 1998
Bedford et al.
phosphaalkenyl ligand in 2a , and thus, a nonlinear Ru-
P-C spine might be reasonably inferred. It is quite
possible that this is a general phenomenon for late
transition metal phosphaalkenyl complexes with high
d-occupancies (cf. nitrosyls), and we are currently at-
tempting to broaden this currently narrow class of
complex to explore this intriguing aspect.
(bta ) benzotriazolyl) to provide the neutral complex
[Ru(PdCHCMe3){H2B(bta)2}(CO)(PPh3)2] (6). Although
the H NMR spectrum of 6 includes a resonance at 0.81
1
due to the CMe3 substituent and a very broad resonance
at 3.95 due to the BH2 group, the resonance due to the
vinylic proton of the phosphaalkenyl ligand could not
be unambiguously distinguished from the myriad of
peaks arising from the phenyl and benzotriazolyl reso-
nances. The 31P{1H} NMR spectrum comprised two
peaks at 391.0 and 28.9 ppm corresponding to the
phosphaalkenyl and phosphine phosphorus nuclei, re-
spectively. The FAB-mass spectrum confirmed the
formulation, with the appearance of a molecular ion in
addition to fragmentations arising from loss of phos-
phine, H2B(bta)2, and PdCHCMe3 groups.
The reaction of [Ru(CHdCHR)Cl(CO)(PPh3)2] with
K[HB(pz)3] (pz ) pyrazol-1-yl) provides the complexes
[Ru(CHdCHR)(CO)(PPh3){HB(pz)3}].21 Similarly, 2a
reacts with K[HB(pz)3] to provide [Ru(PdCHCMe3)(CO)-
(PPh3){HB(pz)3}]. The formulation follows from spec-
troscopic data; however, it proved difficult to isolate this
complex in analytically pure form. A more tractable and
analogous complex was however obtained on treating
2a with 1,4,7-trithiacyclononane ([9]aneS3). Thus, by
analogy with the synthesis of [Ru(CHdCHR)(CO)-
(PPh3)([9]aneS3)]Cl,22 treating a dichloromethane solu-
tion of 2a with [9]aneS3 resulted in the formation of the
salt [Ru(PdCHCMe3)(CO)(PPh3)([9]aneS3)]Cl 7(Cl) which
could be converted to the more crystalline salt 7(PF6)
on treatment with KPF6. As in the previous examples,
coordinative saturation at ruthenium is accompanied by
a shift in the position of the phosphaalkenyl 31P NMR
resonance to higher field (357.3 ppm) and, together with
the value for 5(Cl), these two cationic complexes show
the highest field resonances, relative to the neutral
adducts obtained.
As with the reaction of 2a with CO to provide 3,
isocyanides also add to 2a : Addition of 2,6-dimethy-
phenyl isocyanide to a dichloromethane solution of 2a
results in immediate decoloration to provide [Ru(Pd
CHCMe3)Cl(CO)(CNC6H3Me2-2,6)(PPh3)2] (4b). By anal-
ogy with the reactions of related 5-coordinate vinyl
complexes17,19 it may be assumed that coordination of
the isocyanide occurs trans to the phosphaalkenyl
ligand. The stereochemistry about the equatorial co-
ordination plane does not however follow unambigu-
ously from spectroscopic data. This has, however, been
confirmed for the structurally characterized complex
[RuCl(CO)(PHFCH2CMe3)(CNC6H3Me2-2,6)(PPh3)2]+
which results from the reaction of 4b with excess
HBF4.29 Once again addition of a two electron ligand
to 2a results in a shift of 59 ppm to high field for the
triplet 31P{1H} NMR resonance due the phosphaalkenyl
ligand (391.0 ppm). There is a marginal increase in the
value of 2J (P2P) to 11.1 Hz upon coordinative saturation
of ruthenium. The vinylic proton of the phosphaalkenyl
ligand gives rise to a double triplet resonance at δ 8.12
ppm. The infrared spectrum of 4b includes strong
absorptions due to the isocyanide (2121, 2111sh cm-1
)
and carbonyl (1962 cm-1) ligands. The gross formula-
tion is further supported by the appearance of a molec-
ular ion in the FAB-mass spectrum in addition to
fragmentations due to sequential loss of the phospha-
alkenyl and chloride ligands. In contrast to the facile
decarbonylation of 3, solutions of 4b only slowly dis-
sociate the isocyanide to re-form 2a [ca 5% over 2 days
by IR spectroscopy].
Th ioca r bon yl Com p lexes (Sch em e 3). The thio-
carbonyl ligand CS,31 while superficially analogous to
CO, is a significantly more potent π-acid and is also
more prone to migratory insertion processes.32 We have
previously shown that the hydrido-thiocarbonyl com-
plex [RuHCl(CS)(PPh3)3] (1b)13 reacts with alkynes via
a hydrometalation sequence to provide σ-vinyl com-
plexes analogous to those obtained with 1a . The
subsequent reaction of these complexes with [9]aneS3
provides either the σ-vinyl complex [Ru{C(CO2Me)d
CHCO2Me}(CS)(PPh3)([9]aneS3)]+ or the thioacyl com-
plexes [Ru(η2-SCCRdCHR′)(PPh3)([9]aneS3)]+ depend-
ing on the alkyne employed (Scheme 3).22 A similar
sequence was therefore investigated with PtCCMe3.
Treating 1b with PtCCMe3 provides high yields of the
orange complex [Ru(PdCHCMe3)Cl(CS)(PPh3)2] (2b).
Spectroscopic data for 2b are essentially comparable to
those for 2a with the exception of those associated with
the thiocarbonyl ligand [ν(CS) ) 1267 cm-1(Nujol),
A similar complex [Ru(PdCHCMe3)Cl(CO)(CNCMe3)-
(PPh3)2] (4a ) is obtained on addition of CNCMe3 to 2a
in dichloromethane; however, if excess isocyanide is
added, the salt [Ru(PdCHCMe3)(CO)(CNCMe3)2(PPh3)2]-
Cl 5(Cl) is obtained via replacement of chloride by the
more nucleophilic alkyl isonitrile. Samples of 4a un-
contaminated with 5(Cl) are most conveniently obtained
by carrying out the reaction in diethyl ether suspension,
from which 4a precipitates on formation, prior to
reaction with excess CNCMe3. Metathesis of the coun-
teranion with Na[BPh4] provides the salt 5(BPh4). Once
again a nonlinear phosphaalkenyl ligand is required by
EAN considerations, and this is manifest as a low-field
resonance at 335.9 ppm in the 31P NMR spectrum. In
the solid state (Nujol) both the carbonyl and isocyanide
infrared absorptions are split; however, in dichloro-
methane solution two isocyanide absorptions [ν(CN)
2179, 2156 cm-1] and one carbonyl peak [ν(CO) 2021
cm-1] are observed indicating that the two isocyanide
ligands are mutually cis-coordinated. Thus the stereo-
chemistry is confirmed to be that shown in Scheme 2.
2
δ(13CS) ) 297.7, J (P2C) ) 15.2 Hz]. The complex 2b
reacts with both [Et2NH2][S2CNEt2] and [9]aneS3 to
provide the complex [Ru(PdCHCMe3)(S2CNEt2)(CS)-
(PPh3)2] (8) and the salt [Ru(PdCHCMe3)(CS)(PPh3)-
(31) For a review of the chemistry of coordinated CS see: Broad-
hurst, P. V. Polyhedron 1985, 4, 1801.
(32) Clark, G. R.; Collins, T. J .; Hall, D.; J ames, S. M.; Roper, W. R.
J . Organomet. Chem. 1977, 141, C5. Collins, T. J .; Roper, W. R. J .
Organomet. Chem. 1977, 139, C56. Collins, T. J .; Roper, W. R. J .
Organomet. Chem. 1977, 139, C9. Collins, T. J .; Roper, W. R. J .
Organomet. Chem. 1978, 159, 73.
The facile formation of 5(Cl) points to a lability of the
chloride ligand. Reactions with potentially polydentate
ligands were therefore investigated briefly. As previ-
ously observed for the vinyl complexes [Ru(CHdCHR)-
Cl(CO)(PPh3)2],21 2a reacts readily with K[H2B(bta)2]

Phosphaalkyne Hydrometalation
Organometallics, Vol. 17, No. 21, 1998 4751
Sch em e 3a
Sch em e 4a
a
L ) PPh3 and R ) CMe3.
amples have since emerged and all involve two-
coordinate λ3-phosphorus.34,35
The complex 10 which contains two isocyanide ligands
clearly results from a disproportionation involving loss
of isocyanide from 4a and coordination of this to a
second molecule of 4a . This is supported by the
observation that 5(Cl) is also decomposed slowly by air
to provide 10. The key step appears to involve nucleo-
philic attack by the â carbon of the phosphaalkenyl
ligand upon the cis-carbonyl coligand. This is then
presumably followed by deprotonation of the resulting
metallacycle, the methine proton of which is R to both
a carbonyl and a phosphino group, both of which would
be expected to enhance the acidity. The reaction is slow
(3-5 days), however, on addition of a nonnucleophilic
base (DBU) to 5(Cl) the reaction is accelerated and
complete within 1 h. The proposed neutral metallacyclic
intermediate has so far eluded isolation, being rapidly
oxidized. Thus the proposed mechanism remains con-
jecture. The metallacyclic precursor to 10 might be
viewed as an alternative coordination mode for the
ketenylphosphinidene ligand which has been observed
to result from phosphaalkyne/carbonyl coupling proc-
esses, albeit only in polynuclear systems.36
a
L ) PPh3.
([9]aneS3)]Cl 9(Cl). The former result is not surprising,
in that migratory insertion of thiocarbonyl and vinyl
ligands does not occur when [Ru(CHdCHPh)Cl(CS)-
(PPh3)2] is treated with Na[S2CNMe2], the product being
[Ru(CHdCHPh)(S2CNMe2)(CS)(PPh3)2].30 The latter
result however is significant in that it suggests that the
phosphaalkenyl ligand is less prone to migratory inser-
tion processes than are simple vinyl ligands. The
reactions of 2b with carbon monoxide or isocyanides,
by way of contrast, are complex and have yet to yield
tractable products.
F or m a t ion of a λ5-p h osp h a a lk en yl Com p lex.
While λ3-phosphaalkenyl complexes are now well-
known,8 those based on formally pentavalent phos-
phorus (λ5) have not been described. A λ5-thiaphos-
phaalkenyl ligand has however been proposed as an
intermediate to account for the products of addition of
sulfur to the complex [W{PdC(SiMe3)2}(CO)3(η-C5H5)].28
We have encountered an unusual metallacyclic example
of a λ5-oxaphosphaalkenyl ligand which results from the
slow aerial decomposition of the complex 4a in ethanol.
The complex is formulated as [Ru{η2-P(dO)C(CMe3)C-
(dO)}(CNCMe3)2(PPh3)2] (10) on the basis of spectro-
scopic data and a single-crystal structure determination
(Scheme 4).10 Among the spectroscopic data for 10, the
phosphorus-31 chemical shift for the phosphaalkenyl
group is perhaps the most remarkable in that it is
shifted substantially to high field, appearing as a triplet
at 47.0 ppm [2J (P2P) ) 25.2 Hz] ppm. In the interven-
ing years since Roper’s report of the first example of a
metallacyclic phosphaalkenyl complex,33 very few ex-
Ca r boxyla te Com p lexes. The curious bonding pro-
posed to occur for the complexes 2 remains speculative
(33) Bohle, D. S.; Clark, G. R.; Rickard, C. E. F.; Roper, W. R. J .
Organomet. Chem. 1988, 353, 355. Bohle, D. S.; Rickard, C. E. F.;
Roper, W. R. J . Chem. Soc., Chem. Commun. 1985, 1594.
(34) Binger, P.; Haas, J .; Herrmann, A. T.; Langhauser, F.; Kru¨ger,
C. Angew. Chem., Int. Ed. Engl. 1991, 30, 310.
(35) Binger, P.; Biedenbach, B.; Mynott, R.; Kru¨ger, C.; Betz, P.;
Regitz, M. Angew. Chem., Int. Ed. Engl. 1988, 27, 1157.
(36) Gaeda, P. E.; J ohnson, B. F. G.; Nixon, J . F.; Nowotny, M.;
Parson, S. Chem. Commun. 1996, 1455. Al-Resayes, S. I.; Hitchcock,
P. B.; Nixon, J . F. Chem. Commun. 1987, 928. Hitchcock, P. B.; Maah,
M. J .; Nixon, J . F. Heteroat. Chem. 1991, 2, 243.

4752 Organometallics, Vol. 17, No. 21, 1998
Bedford et al.
the ruthenium-oxygen bond trans to the phospha-
alkenyl ligand is very significantly longer (37σ) at
2.366(5) Å than that to O(8) [2.182(5) Å]. Excluding
O(6), the geometry at ruthenium becomes only lightly
distorted square-based pyramidal, with cis-ligand angles
in the range 86.2(2)-94.5(2)°. The ruthenium atom is
displaced by only 0.10 Å above the plane defined by P(2),
P(3), C, and O(8), in the direction of P(1), thus further
emphasizing the strong trans influence of the phos-
phaalkenyl ligand and the corresponding weak Ru-O(6)
linkage. The formate ligand does not extend signifi-
cantly beyond the steric shield of the “Ru(PPh3)2” double
cone, precluding intermolecular interactions. Hence the
asymmetry may be attributed exclusively to electronic
effects at the ruthenium center.
The phosphaalkenyl ligand provides the primary focus
of interest. Previous examples of structurally charac-
terized “1-electron” phosphaalkenyl complexes8 include
[Fe{PdC(SiMe3)2}(CO)2(η-C5Me5)],37 [Fe{PdC(NMe2)2}-
(CO)2(η-C5Me5)],38 [Fe{PdC(SiMe3)OSiMe3}(CO)2(η-
C5H5)],39 and the recently reported complex [Fe-
{PdCHNPhNdC(NMe2)2}(CO)2(η-C5Me5)].40 However,
as noted in the Introduction, all these involve sterically
cumbersome and/or π-interactive substituents which
may be expected to influence the structural as well as
the reactivity features. In these complexes the PdC
mutliple bonds and the Fe-PdC angles fall in the
ranges 1.680(9)-1.709(5) Å and 109.67(6)-126.2(3)°,
respectively.
In the complex 11a the trans regiochemistry is clearly
evident at the P(1)-C(1) multiple bond, resulting from
cis addition of the ruthenium hydride, thus confirming
the regiochemistry proposed for 2 and derived com-
plexes. The angle at P(1) is almost perfectly trigonal
at 119.1(3)°. The P(1)-C(1) bond of 1.640(8) Å is clearly
multiple; indeed, it is the shortest such separation to
be observed for a 1-electron phosphaalkenyl ligand. The
angle at C(1) is opened somewhat from the ideal sp2-
trigonal value [P(1)-C(1)-C(3) 127.4(7)]. The equato-
rial donor atoms of the coordination sphere and the
atoms C(1), C(2), C(7), and O are essentially coplanar
with the maximum deviation being only 0.06 Å by P(1).
The Ru-P(1) separation of 2.295(2) Å is significantly
shorter than the ruthenium phosphine distances of
2.378(2) and 2.386(2) Å (by ca. 44σ).
The phosphaalkene complexes [Ru(MePdCHCMe3)-
ClI(CO)(PPh3)2],41 [Ru{P(AuPPh3)dCHCMe3}Cl2(CO)-
(PPh3)2],42 and [Ru{P(HgC5H4Fe(η-C5H5))dCHCMe3}-
Cl2(CO)(PPh3)2]43 have respectively Ru-P bond lengths
of 2.280(2), 2.296(2), and 2.277(4) Å and PdC bond
lengths of 1.657(8), 1.664(9), and 1.69(2) Å. These
phosphaalkene complexes are derived from electrophilic
attack at the phosphaalkenyl ligand of 2a , and it is
F igu r e 1. (a) Top: Molecular structure of the complex 11a ,
showing 40% probability thermal ellipsoids, with methyl
and phenyl H atoms omitted for clarity. (b) Bottom: View
normal to equatorial coordination plane of 11a with phos-
phine ligands omitted.
in the absence of accurate structural information. In
an alternative approach to investigating this aspect, we
reasoned that replacement of the chloride ligand by a
weakly bidentate chelate might provide insight through
differential trans influences for the phosphaalkenyl and
carbonyl ligands. The reaction of 2a with carboxylate
salts was therefore investigated. A rapid reaction
ensues between 2a and the sodium salts of formic and
ferrocenecarboxylic acids to provide the complexes
[Ru(PdCHCMe3)(O2CR)(CO)(PPh3)2] (R ) H (11a ),
C5H4Fe(η-C5H5) (11b)). Spectroscopic data for these two
derivatives (Experimental Section) are unremarkable
alongside those for complexes 3-9. The complex 11a
provided crystals suitable for X-ray analysis, the results
of which are summarized in Tables 1 and 2 and Figure
1.
(37) Gudat, D.; Niecke, E.; Arif, A. M.; Cowley, A. H.; Quashie, S.
Organometallics 1986, 5, 593.
(38) Weber, L.; Kaminski, O.; Stammler, H.-G.; Neumann, B.; Boese,
R. Z. Naturforsch., B 1993, 48, 1784.
(39) Weber, L.; Reizig, K.; Frebel, M.; Boese, R.; Polk, M. J .
Organomet. Chem. 1986, 306, 105.
(40) Weber, L.; Scheffer, M. H.; Beckmann, E.; Stammler, H.-G.;
Neumann, B. Organometallics 1997, 16, 2958.
(41) Bedford, R. B.; Hill, A. F.; J ones, C.; White, A. J . P.; Williams,
D. J .; Wilton-Ely, J . D. E. T. J . Chem. Soc., Dalton Trans. 1997, 139,
1113.
(42) Bedford, R. B.; Hill, A. F.; J ones, C.; White, A. J . P.; Williams,
D. J .; Wilton-Ely, J . D. E. T. Chem. Commun. 1997, 179.
(43) Hill, A. F.; J ones, C.; White, A. J . P.; Williams, D. J .; Wilton-
Ely, J . D. E. T. J . Chem. Soc., Dalton Trans. 1998, 1419.
The geometry at ruthenium may be described as
distorted octahedral with the primary distortion arising,
as expected, from the small bite angle of the formate
chelate [O(6)-Ru-O(8) 57.1(2)°]. The formate is, how-
ever, very asymmetrically bound to ruthenium such that

Phosphaalkyne Hydrometalation
Organometallics, Vol. 17, No. 21, 1998 4753
noteworthy that conversion of the phosphaalkenyl ligand
into a coordinated phosphaalkene is not accompanied
by crystallographically significant changes in the Ru-P
or P-C bond lengths. Nevertheless, it has been argued
that a π-acidic component to the bonding in the phos-
phaalkene complexes contributes to the short Ru-P
bond lengths. It therefore seems likely that the Ru-
P(1) bonding in 11a also involves a modest π-component,
consistent with the adopted orientation of this ligand
such as to maximize π-retrodonation from ruthenium.
That this feature is a result of the unsaturated P(1)d
C(1) linkage follows from the observation that, in the
conventional phosphido complex [Os(PHPh)Cl(CO)2-
(PPh3)2],44 the osmium phosphido bond [2.523(7) Å] is
significantly longer (15σ) than those involving the
phosphine ligands [2.414(7), 2.423(6) Å].
Con clu d in g Rem a r k s. The hydrometalation of
phosphaalkynes has been demonstrated for the first
time. Following our preliminary communication,9 the
hydrostannylation of free phosphaalkynes has been
reported.11 Furthermore, the hydrozirconation of a
platinum-coordinated phosphaalkyne has been recently
observed by Nixon.45 Taken together, these observation
show that phosphaalkyne hydrometalation is a poten-
tially useful method for the functionalization of phos-
phaalkynes. In the present case, the hydroruthenation
process leads to versatile complexes of phosphaalkenyl
ligands which do not require the presence of kinetically
or thermodynamically stabilizing substituents at car-
bon. These serve as useful precursors to a wide range
of phosphaalkenyl complexes. The reactivity and spec-
troscopic characteristics of the complexes 2 suggest a
curious situation which appears to fall outside the
previously dichotomous 1- or 3-electron-donating roles
for such ligands. The inferred nonlinear nature of the
Ru-P-C spine, not predicted by EAN considerations,
renders the phosphorus nucleophilic, and the reactions
of complexes 2 with electrophilic reagents will form the
basis of a subsequent report.30
Ack n ow led gm en t. We are grateful to the EPSRC
(U.K.) for financial support and the award of a student-
ship (to J .D.E.T.W.-E). Ruthenium salts were gener-
ously donated by J ohnson Matthey Ltd. A.F.H. grate-
fully acknowledges the award of a Senior Research
Fellowship by the Leverhulme Trust and The Royal
Society.
Su p p or tin g In for m a tion Ava ila ble: Tables of X-ray
parameters, final atomic positional parameters and isotropic
and anisotropic thermal parameters, and bond distances and
angles and an ORTEP diagram for the structural analysis (8
pages). Ordering information given on any current masthead
page.
(44) Bohle, D. S.; J ones, T. C.; Rickard, C. E. F.; Roper, W. R.
Organometallics 1986, 5, 1612.
(45) Benvenutti, M. H. A.; Cebac, N.; Nixon, J . F. Chem. Commun.
1997, 1327.
OM980204C